Mitsubishi has agreed to acquire a 20% ownership interest in an offshore oilfield offshore Ivory Coast from Anadarko Petroleum.
The company will buy the stake in the deepwater oilfield block CI-103, located about 50km off the coast of Cote d'Ivoire.
The transaction is subject to approvals from Côte d'Ivoire Government.
Anadarko Petroleum currently holds a 55% stake in the block, while Tullow Oil and Petroci have 30% and 15% stakes, respectively.
The partners have secured approval to go ahead with appraisal operations and identified oil and gas deposits at an exploratory well that was drilled in 2012.
A final investment decision on the project is expected to be made by the end of 2015.
Additional evaluation works for deposits, including carrying out shallow hazard surveys and drilling further appraisal wells, will go ahead with Mitsubishi as a new entrant.
Mitsubishi said this particular project is important to the company due to its role in Côte d'Ivoire's economic development.
The Ivory Coast oil ministry signed 18 production-sharing agreements between 2012 and 2013.
Companies, such as Anadarko, have drilled ten wells in 2013 alone and crude production at the CI-103 oilfield is expected to start in 2019.
The Ivory Coast oil field acquisition adds to Mitsubishi's existing African upstream assets in Angola, Liberia and Gabon.
Mitsubishi also has assets in south-east Asia, the US Gulf of Mexico, the UK North Sea and Australia.